Sterilization cassettes are typically a square or rectangle box with a bottom, or body and a mating lid; the lid is often held to the bottom with a hinge. Traditionally most cassettes are made of stainless steel sheet material which has been perforated to allow sterilizing steam to enter the cassette. A cassette blank is bent to form a shallow sided box with the backside of the box often including hinge cleats. Box depth is typically ¾ inch to 2 inches. The lid is similarly constructed. The lid can also have a series of hinge cleats along one side. Sterilization cassettes can also be made of resin. The lid and box are fastened to one another to trap instruments to be sterilized inside. Traditionally, the lid is connected to the box on one side by a hinge and fastened on the other with a clip or latch. Alternatively, the lid can be secured to the box with an arrangement of slots and mating tabs. This allows the lid to be removed from the box after sterilization. Deficiencies in the latching or fastening mechanism used to secure the lid to the bottom compartment cause a great deal of consternation in many available cassette designs.
The interior of a cassette can contain a series of standoff rails to hold long instruments and divided compartments to hold small or inconsistently shaped instruments. Rivets and/or spot welding secure the internal dividers and rails, or if the cassette is made of resin these dividers are injection molded. Traditionally, instrument rails have some sort of scalloped design or extended fork slots in which to align and hold the instruments side by side in the bottom of the cassette. Most commonly these bottom rails are made of stainless steel or are a silicone strips attached to the bottom of the main compartment. Instruments are dropped into scalloped cradles in the rail or pressed between flexible silicone fingers on the silicone strip to securely retain the instruments in the cassette. If stainless steel instrument scalloped rails are used, a strip of silicone tubing is attached across the lid, thereby providing a means to retain the instruments within the scalloped cradles when the lid is closed protecting the instruments from damage during the sterilization procedure. The scallops or fingers of a rail are arranged to accommodate a maximum number of instruments. This causes difficulty however when there is not enough space between neighboring instruments to allow the clinician to remove the chosen instrument in a safe manner. The clinician is forced to grab the instrument by its sharp working end where there is adequate finger room to remove it from the cassette. Sterility can be compromised if the sharp end cuts through the glove on a hand.
Current cassette lids use silicone exclusively as a means of retention to hold instrument in place. It is becoming increasingly undesirable to use silicone in or on products that require sterilization. It has been recognized that silicone traps debris beneath its layer and shields or insulates that debris from the effects of sterilization.
A need remains for a sterilization cassette with a reliable, easy to use latching system with an internal configuration that holds instruments conveniently for the clinician yet holds them securely and without the use of silicone.
All patents, patent applications, provisional patent applications and publications referred to or cited herein, are incorporated by reference in their entirety to the extent they are not inconsistent with the teachings of the specification.